<template>
  <view>
    <my-search @click="gotoSearcha"></my-search>
    <view class="scroll-view-container">
      <!--左侧的滑动区域-->
      <scroll-view class="left-scroll-view" scroll-y :style="{height: wh+'px'}">
        <block v-for="(item, i) in cateList" :key="i">
          <view :class="['left-scroll-view-item',i===active?'active':'']" @click="activeChange(i)">{{item.cat_name}}
          </view>
        </block>
      </scroll-view>
      <scroll-view class="right-scroll-view" scroll-y :style="{height: wh+'px'}" :scroll-top="scrollTop">
        <view class="cate-lv2" v-for="(item2, i2) in cateLevel2" :key="i2">
          <view class="cate-lv2-title">{{item2.cat_name}}</view>
          <view class="cate-lv3-list">
            <!--三级分类-->
            <view class="cate-lv3-item" v-for="(item3,i3) in item2.children" :key="i3" @click="gotoGoodList(item3)">
              <!--三级分类图片-->
              <image :src="item3.cat_icon"></image>
              <!--三级分类文本-->
              <text>{{item3.cat_name}}</text>
            </view>
          </view>
        </view>
      </scroll-view>
      <!--右侧滑动区域-->
    </view>
  </view>
</template>

<script>
  import badgeMix from '@/mixins/tabbar-badge.js'

  export default {
    // 将 badgeMix 混入到当前的页面中进行使用
    mixins: [badgeMix],
    data() {
      return {
        wh: 0,
        cateList: [],
        active: 0,
        cateLevel2: [],
        scrollTop: 0
      };
    },
    onLoad() {
      const sysInfo = uni.getSystemInfoSync()
      this.wh = sysInfo.windowHeight - 50
      this.getCateList()
    },
    methods: {
      async getCateList() {
        // 发起请求
        const {
          data: res
        } = await uni.$http.get('https://api-hmugo-web.itheima.net/api/public/v1/categories')
        // 判断是否获取失败
        if (res.meta.status !== 200) return uni.$showMsg()
        // 转存数据
        this.cateList = res.message
        this.cateLevel2 = res.message[0].children
      },
      activeChange(i) {
        this.active = i
        this.cateLevel2 = this.cateList[i].children
        this.scrollTop = this.scrollTop === 0 ? 1 : 0
      },
      gotoGoodList(item3) {
        uni.navigateTo({
          url: "/subpkg/goods_list/goods_list" + "?cid=" + item3.cat_id
        })
      },
      gotoSearcha() {
        uni.navigateTo({
          url: '/subpkg/search/search'
        })
      }
    }
  }
</script>

<style lang="scss">
  .scroll-view-container {
    display: flex;
  }

  .left-scroll-view {
    width: 120px;
  }

  .left-scroll-view-item {
    line-height: 60px;
    background-color: #f7f7f7;
    text-align: center;
    font-size: 12px;

    &.active {
      background-color: #ffffff;
      position: relative;

      // 渲染激活项左侧的红色指示边线
      &::before {
        content: ' ';
        display: block;
        width: 3px;
        height: 30px;
        background-color: #c00000;
        position: absolute;
        left: 0;
        top: 50%;
        transform: translateY(-50%);
      }
    }
  }

  .cate-lv2-title {
    font-size: 12px;
    font-weight: bold;
    text-align: center;
    padding: 15px 0;
  }

  .cate-lv3-list {
    display: flex;
    flex-wrap: wrap;

    .cate-lv3-item {
      display: flex;
      width: 33.3%;
      flex-direction: column;
      align-items: center;
      margin-bottom: 10px;

      image {
        width: 60px;
        height: 60px;
      }

      text {
        font-size: 12px;
      }
    }
  }
</style>
